A reciprocating pump of this kind is a large-capacity (the discharge amount per unit time is large) reciprocating pump in which one pair of diaphragms such as bellows are mounted in a back-to-back configuration in the pump body, and tip end portions of the diaphragms are interlockingly connected to each other by connecting rods which are placed in the lateral outsides so as to detour around the diaphragms, whereby the pair of diaphragms are complementarily expanded and contracted to continuously perform pumping. For example, the pump disclosed in Patent Reference 1 is known.
As shown in FIG. 2 of Patent Reference 1, namely, in order to complementarily expand and contract bellows 12a, 12b which are opposedly placed, connecting plates 32a, 32b fixed to pump shafts 24a, 24b attached to the tip ends of the bellows 12a, 12b are interlockingly connected to each other by a pair of connecting rods 34a, 34b, and the pair of pump shafts 24a, 24b, the pair of connecting plates 32a, 32b, and the pair of connecting rods 34a, 34b are reciprocally moved as an integral moving body.
Means for slidably supporting the moving body which is configured by the plural components as described above allows the pump shafts 24a, 24b to be passed through holes 22a, 22b of pump flanges 1a, 1b through bearings 23a, 23b. Namely, the moving body which is a large structure has a configuration which is slidably supported only by the pump shafts 24a, 24b.     Patent Reference 1: JP-A-2002-174180